Ghost in the machine (resolved, loose couplers)

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martyscncgarage
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Re: Ghost in the machine

Post by martyscncgarage »

Please post a FRESH Report
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
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Location: Mesa, AZ

Re: Ghost in the machine

Post by martyscncgarage »

tuffduck wrote: Wed Apr 28, 2021 7:31 pm Thanks, I think this is the culprit. The set screws are tight but I notice a little jarring motion a couple of times. I will take it apart tomorrow and loctite the couplers to the shaft.
Where are the bolts for that pillow block bearing? Check all the mechanicals as Keith mentioned.
Marc has a good routine for testing backlash. From his website: http://www.cncsnw.com/LashHowTo.htm
Run it as a test...

If you have a stepper driven machine, you may be pushing the Y axis too hard and loosing steps.
Try and temporarily reduce your rapids and feed rate and see if the problem improves.

DO post a FRESH report
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
tuffduck
Posts: 359
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Location: Scotland, ON, Canada

Re: Ghost in the machine

Post by tuffduck »

Here is a fresh report. I tried reducing the rapids and nothing changed. I have included images. The pillow block bearings were welded on by the fabricator.

I went through the update schematics for V4.64 and noticed this diagram for Gecko 201X drives. Is the DB25 board required? My machine was working fine without it.
Attachments
report_0479B7E7BDC2-0205202948_2021-05-07_11-17-32.zip
(1.92 MiB) Downloaded 77 times
S14977-ACORN_rev4_GECKO_G201_STEPPER_DRIVE.pdf
(194.96 KiB) Downloaded 73 times
IMG_20210507_111944.jpg
cnckeith
Posts: 7164
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Re: Ghost in the machine

Post by cnckeith »

i don't see anything wrong with your configuration that would cause this...
go back and look at the machine itself, my guess is slip or drag.
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
tuffduck
Posts: 359
Joined: Mon Mar 02, 2020 5:07 pm
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Location: Scotland, ON, Canada

Re: Ghost in the machine

Post by tuffduck »

Okay, thanks, checked everything, adjusted a couple things. Added another set screw to the he motor hub and loctited the hub and key in place. Will run it again to see the results.
tuffduck
Posts: 359
Joined: Mon Mar 02, 2020 5:07 pm
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Location: Scotland, ON, Canada

Re: Ghost in the machine

Post by tuffduck »

Ran more parts today. First 7 no problem. The next set of 4 was entirely different. Pictures and report attached.
Attachments
report_0479B7E7BDC2-0205202948_2021-05-08_20-01-15.zip
(1.89 MiB) Downloaded 78 times
IMG_20210508_193206.jpg
IMG_20210508_193101__01.jpg
cnckeith
Posts: 7164
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Re: Ghost in the machine

Post by cnckeith »

something is loose
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
tuffduck
Posts: 359
Joined: Mon Mar 02, 2020 5:07 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Scotland, ON, Canada

Re: Ghost in the machine

Post by tuffduck »

Running out of ideas of what and how to fix it. I am thing of adding extra collars to the pillow block bearings. There is nothing left to tighten.
https://bearingfinder.ntnamericas.com/i ... lars/el208
Attachments
download.jpeg
download.jpeg (4.88 KiB) Viewed 2137 times
tuffduck
Posts: 359
Joined: Mon Mar 02, 2020 5:07 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Scotland, ON, Canada

Re: Ghost in the machine

Post by tuffduck »

I sent photos of what happening as well as photos of the bearings to a local bearing supplier to find out that they were eccentric collars vs concentric collars, so they would lock in one direction and loosen in the opposite direction. Replaced them today any ran parts and all is checking out so far. Thanks everyone for your efforts.
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